This invention relates to elongated, flexible clips having a plastic covering on a metal core. Such clips are used for appearance and to form seals along a flange formed at an edge of an object. A common application of such clips is in vehicles, such as automobiles, boats and motorcycles, where the clips are disposed along doors, windows and other elements including openings or edges.
Clips of the type related to the invention include a metal core that gives the clip strength, and at least some of its shape and its gripping capacity, while retaining flexibility. The metal core is coated with a plastic material, i.e., a material that is flexible such as a synthetic rubber or a plastic, that has an aesthetically acceptable surface and that is pliable so that a fluid-tight seal can be formed with another object. Generally, the metal core is formed into a U-shape or a similar shape that includes a narrowed throat and larger enclosure. A prepared flange on an object, such as an automobile door edge, is inserted into the throat of the clip. The metal core of the clip permits deflection of the clip legs while the flange is being inserted into the clip throat. Once the flange is in place, the deflected legs of the metal core exert clamping forces that secure the clip to the flange.
Clips of the type just described are manufactured in very long, continuous lengths. In order to use the clip material efficiently in manufacturing, the continuous lengths are severed into selected lengths. For example, in automobile manufacturing, a supplier provides lengths of clip material cut to the manufacturer,s specifications. Because of normal variations in the cut lengths of the clips and in the dimensions of the parts to which the clips are applied, a clip length may occasionally be slightly shorter than desired. In this situation, a gap will be left between one or both of the ends of the clip and the surface or surfaces those ends are intended to abut. In order to avoid the undesired appearance given by a too-short clip, some clips, depending on the construction of their metal cores, may be stretched to the desired length by applying tensile forces. However, in known clips, the outer covering, particularly if it is a plastic, exerts restorative, compressive forces on a stretchable clip that has been extended. These forces will, over time, shrink the clip toward its original length. That is, the undesired gap or gaps produced by a shortened clip that may be stretched are only temporarily avoided by the stretching and eventually reappear.
Accordingly, it would be desirable to provide a clip of the type described that could be slightly stretched by applying tensile forces, that would not lose its flexibility in the stretching and that would resist subsequent shrinkage.